/*
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * This software is open source.
 * See the bottom of this file for the licence.
 */

package org.dom4j.tree;

import org.dom4j.Element;
import org.dom4j.Namespace;

/**
 * <p> <code>DefaultNamespace</code> implements a doubly linked node which
 * supports the parent relationship and is mutable. It is useful when returning
 * results from XPath expressions. </p>
 * 
 * @author <a href="mailto:jstrachan@apache.org">James Strachan </a>
 * @version $Revision: 1.2 $
 */
public class DefaultNamespace extends Namespace
{
   /** The parent of this node */
   private Element parent;

   /**
    * DOCUMENT ME!
    * 
    * @param prefix is the prefix for this namespace
    * @param uri is the URI for this namespace
    */
   public DefaultNamespace(String prefix, String uri)
   {
      super(prefix, uri);
   }

   /**
    * DOCUMENT ME!
    * 
    * @param parent is the parent element
    * @param prefix is the prefix for this namespace
    * @param uri is the URI for this namespace
    */
   public DefaultNamespace(Element parent, String prefix, String uri)
   {
      super(prefix, uri);
      this.parent = parent;
   }

   /**
    * DOCUMENT ME!
    * 
    * @return the hash code based on the qualified name and the URI of the
    *         namespace and the hashCode() of the parent element.
    */
   protected int createHashCode()
   {
      int hashCode = super.createHashCode();

      if(parent != null)
      {
         hashCode ^= parent.hashCode();
      }

      return hashCode;
   }

   /**
    * Implements an identity based comparsion using the parent element as well
    * as the prefix and URI
    * 
    * @param object DOCUMENT ME!
    * 
    * @return DOCUMENT ME!
    */
   public boolean equals(Object object)
   {
      if(object instanceof DefaultNamespace)
      {
         DefaultNamespace that = (DefaultNamespace) object;

         if(that.parent == parent)
         {
            return super.equals(object);
         }
      }

      return false;
   }

   public int hashCode()
   {
      return super.hashCode();
   }

   public Element getParent()
   {
      return parent;
   }

   public void setParent(Element parent)
   {
      this.parent = parent;
   }

   public boolean supportsParent()
   {
      return true;
   }

   public boolean isReadOnly()
   {
      return false;
   }
}

/*
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided that the
 * following conditions are met:
 * 
 * 1. Redistributions of source code must retain copyright statements and
 * notices. Redistributions must also contain a copy of this document.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * 3. The name "DOM4J" must not be used to endorse or promote products derived
 * from this Software without prior written permission of MetaStuff, Ltd. For
 * written permission, please contact dom4j-info@metastuff.com.
 * 
 * 4. Products derived from this Software may not be called "DOM4J" nor may
 * "DOM4J" appear in their names without prior written permission of MetaStuff,
 * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
 * 
 * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
 * 
 * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 */
